In engine systems having internal combustion engines, a series of electrically drivable position encoders is used, as a rule, whose actuation positions are recorded by suitable sensors, so that when the respective position encoder is driven, its respective actuation position can be checked. Examples of such position encoders are, for instance, a throttle valve in an air supply system for the respective internal combustion engine, an exhaust gas recirculating valve, a wastegate valve for controlling a turbocharger and the like.
An electrical DC motor (position encoder motor) is used, as a rule, as the drive for the position encoders. As is known for DC motors, the polarity of the electrical variable (supply voltage), by which the DC motor is controlled, is essential for the direction of a change of a position encoder position.
In early development stages in particular, in which electrical connections in the overall system are wholly or partially not developed with the aid of plug contacts that are protected from polarity reversal, the mixup of connecting lines may occur because of wiring harness discrepancies, faulty configurations of the most computer-oriented software or faulty pin positioning, so that the driving of the position encoder is wrongly directed and/or the feedback of the position encoder sensor, situated on the position encoder, is faulty. In the case of a mixup of terminals of the position encoder motor and/or in the case of a mixup of terminals of the position encoder, under certain circumstances, by the simple plausibility check of the position encoder function, the position feedback of the position encoder sensor is misguided when searching for a fault, so that the fault search may become costly.